Shuttle Discovery astronauts are making the first of two spacewalks this week to carry out maintenance tasks on the exterior of the International Space Station (ISS).

Steve Bowen and Alvin Drew will spend more than six hours outside the orbiting platform, preparing it for the installation of a new store room.

Discovery arrived at the ISS on Saturday.

It is the ship’s final mission into space before being retired to a museum.

Bowen is making a small piece of history, himself. He was called up late for the mission following a bicycle injury to the assigned lead spacewalker Tim Kopra.

It means Bowen is on consecutive shuttle trips having flown on Atlantis in May last year – the first time that has ever happened.

“There’s a lot of things I don’t know that I’m trying to catch up,” Bowen said on Sunday. “But these guys have been training together for so long, they know this mission so well they’ve been able to pick up the slack that I kind of brought on board. They’ve got me covered pretty well.”

A key task for the Discovery crew on this flight is to fit a Italian-built logistics module known as Leonardo permanently to the space station.

The module, which has been used down the years as a packing box for supplies in the orbiter’s payload bay, would normally return to Earth with every shuttle mission, but for Discovery’s flight it is being left on station to provide extra storage space.

The attachment, to the Unity connecting node, requires Bowen and Drew to move some cabling. In their spacewalk, the pair will also replace a fault pump needed to push ammonia coolant around the platform.

Leonardo will be lifted into place on Tuesday this week; a follow-up spacewalk will then take place on Wednesday.

Discovery is due back on Earth on Monday, 7 March. The orbiter is expected eventually to go to the Smithsonian Institution’s Air and Space Museum.

Steven Lindsey, Shuttle Commander, said it was a real privilege to be on the shuttle’s final flight